1 Ваywatch A lifeguard (L) is standing on the beach when he spots a distressed surfer (S). The lifeguard is distance a = 20m from the shore. The surfer is distance b = 20 m out to sea and d = 100 m down shore. The lifeguard, an exceptional athlete, can run at a top speed of 10 m/s and swim at a top speed of 2.5 m/s. (a) How long will it take the lifeguard to reach the swimmer if he travels along the path of least distance? (b) How long will it take the lifeguard to reach the swimmer if he travels along the path of least time? d S осean b a beach L

1 Ваywatch A lifeguard (L) is standing on the beach when he spots a distressed surfer (S). The lifeguard is distance a = 20m from the shore. The surfer is distance b = 20 m out to sea and d = 100 m down shore. The lifeguard, an exceptional athlete, can run at a top speed of 10 m/s and swim at a top speed of 2.5 m/s. (a) How long will it take the lifeguard to reach the swimmer if he travels along the path of least distance? (b) How long will it take the lifeguard to reach the swimmer if he travels along the path of least time? d S осean b a beach L